The present invention relates to a method of forming coatings using compositions comprising borosilazanes and fillers. These coatings are useful on a variety of electronic substrates.
The use of borosilazanes to form ceramic coatings is known in the art. For instance, references such as U.S. Pat. Nos. 4,482,689 and 4,910,173 and European Patent Nos. 364,323 and 424,082 teach borosilazanes which can be used to form such coatings. These references, however, do not teach the use of borosilazanes with fillers as coating compositions on electronics.
The use of polysilazanes to form ceramic coatings on electronic devices is also known in the art. For instance, International Publication WO 93/02472 discloses a process for forming a coating on an electronic substrate wherein a solution of a polysilazane resin is applied to an electronic substrate followed by heating the coated substrate in air at a temperature in the range of 150.degree.-800.degree. C. This reference, however, does not describe the use of borosilazane nor the use of fillers within the coating.
Similarly, the use of fillers within ceramic coatings derived from polysilazanes is also known in the art. For instance, Japanese Patent Application Numbers 52287, 221466 and 3250082 describe compositions comprising polysilazanes and fillers. These references, however, do not describe the use of borosilazanes.
U.S. Pat. No. 4,973,526 teaches a method of forming coatings containing silicon, oxygen and boron. The method taught therein comprises mixing hydrogen silsesquioxane resin with a boron oxide precursor, coating an electronic device with the mixture and heating the coated device to ceramify the coating. This reference, however, does not describe the use of borosilazanes nor the incorporation of fillers.
The present inventors have now discovered that useful coatings can be formed from compositions comprising borosilazanes and fillers.